This book provides a comprehensive presentation of Earth's energy flows and their consequences for the climate. The Earth's climate as well as planetary climates in general, are broadly controlled by three fundamental parameters: the solar irradiance, the planetary albedo and the planetary emissivity. Space measurements indicate that these three quantities are remarkably stable. A minor decrease inplanetary emissivity is consistent with theoretical calculations. This is due to the ongoing increase of atmospheric greenhouse gases making the atmosphere more opaque to long wave terrestrial...